The invention relates generally to systems and methods for displaying data in windows on display devices and more particularly to systems and methods that facilitate view panning for multiple display devices.
Virtual desktops are known which allow a computer user or other display device user to view additional surface space on a virtual desktop. For example, a user may move a position indicator, such as a cursor, across a viewing area on a screen and as the cursor moves the data displayed on the screen changes to give the appearance that the user is moving across the top of the desk. The desktop (i.e., the surface) is larger than the viewing area presented on the display device. In conventional graphics controller chips and other display device control systems, a user may define a surface mode by indicating how a surface is configured such as the height, width, color depth and refresh rate to configure surface dimensions.
Graphics controller chips or graphics adapter chips are known which output display data to multiple displays such as an LCD display or a CRT monitor. Such graphics adapters or graphics controller chips have to accommodate the timing differences of the various displays such as differing refresh rates and resolutions. Conventional graphics controller chips use separate memory controllers to configure both displays and to display different data on both displays such as movies on one display and text on another display or both movies and text on the same display.
The virtual desktop arrangement allows the user to see other documents other than the one the user may be using by panning across the desktop. Conventional graphics controller chips for example, define a view area which is often selectable in size by a user. With dual or multiple displays, a separate desktop or surface is defined for each display device. Independent data is shown on two distinct desktops. For example, display devices typically display two different surfaces on the two different displays and hence there is a discontinuous surface being shown and displayed on each display device. To draw an image for example, multiple controllers must identify and compute image data for two memory surfaces, one surface being associated with each display device. This can unnecessarily limit the available working surface.
Other systems are known that utilize one desktop surface and breakup the surface into separate pieces on multiple displays to display one piece on one display and another piece on another display. However, such systems typically only show one-half of each surface on each display. The combinations of the two displays equals the entire desktop surface. Such systems do not also typically offer the capability of panning to see the entire surface from both displays. Also, conventional display systems typically limit a user""s ability to view an entire surface when the surface is larger than the display areas on multiple display screens. Moreover, conventional systems typically do not allow a user to pan continuously across multiple viewing areas to allow multiple screens to be used as a single larger screen or an even larger desktop surface over which to navigate.
Consequently a need exists for an improved display system that can afford increased flexibility in utilizing surfaces, such as virtual desktops, when using multiple display devices. It would be desirable if such a system used a single graphics adapter to generate a multiple view panning system for multiple display devices.